Apparatus for the detection of dangerous gases.



F. J. TURQUAND & W. E. GRAY. APPARATUS FOR THE DETECTION OF DANGEROUS GASES.

APPLIGATION FILED NOV. 4,1910

1,016,305. Patented Feb. 6, 1912.

.oflice addresses are 4 and '5 Albany UNITED S'11 l ES PATENT OFFICE.

rnnnnmcx muss munouann AND wrmim nnwm eas or Lennon, ENGLAND.

APPARATUS FOR THE DETECTION OF DANGEROUS Specification of Letters Patent.

Application flledliovemlier 4, 1910, Serial No. 590,670.

T 0 all whom'it may concern Be it known that we, FREDERICK JAMES TURQUANI) and WILLIAM EDWIN GRAY, subjects of the King of Great Britain, and residents of London, England, (whose ostourt Yard, Piccadilly, in the county of London, England, and 53 Bayham .Place, Camden Town, in the county of London aforesaid, respectively,) have invented certain new and useful Improvements in Apparatus for the Detection of Dangerous Gases, of which the following is a specification.

This invention relates to thatclass of apparatus known as diifusimeters, that are adapted to utilize the law of gaseous diffusion according to which, for example, a

' light gas or gas of low density or specific gravity is found to be capable of diffusing through a porous medium at a greater velocity than is the case with a gas of higher specific gravity. By retaining one of the gases 1n a chamber, whose only co-mmunica tion with the exterior where the other gas may be presumed to be, is by way of a porous medium, an increase or decrease of pressure results in' the chamber, which maybe shown by a suitable indicator in communication therewith. v

The present invention, broadly speaking, consists of a diifusimet-er having two diffusing chambers, with an indicator between them, the whole forming whatmight be termed a differential, diffusimeter. particularly adapted to detect the presence of deleterious or explosive gases in coal mines and other places.

In addition to the main porous septa of the difi'usion chambers, we may provide auxiliary porous septa each communicating .between' one of the chambers and a ,fresh gas reservoir '.for communicating. with. each other and so ad uSted or constructed that diffusion only takes place slowly therethrough; this fresh gas reservoir .being of necessity a closed chamber, any i change of temperature would give, rise to expanded or contracted will serve to keepthe pressure constant. Obviously, other means may be employed to produce the same result. v

to those forms oft-he apparatus particularly Patented Feb. 6,1912.-

applicable for use 'in coal mines or other places wherein various gases are to be tested and in which ready access to fresh air is not obtainable. I

i The. apparatus may conveniently be fitted at the top of a safety or, other lamp, and in order to facilitate observation of the indicator alens may be mounted and suitably arranged above the same.

The accompanying drawings illustrate suit-able forms of the present invention, Figure 1 being a perspective view '(partbroken' away) of a form particularly adapted for use with certain kinds of miners lamps, and Fig. 2 -is a view of a detail; Fig. 3 is also a perspective view (part broken away). of another form. Fig. 4 is a view, on an'enlarged scale, of adet-ail;.Fig. 5 is a plan (with partbroken away) of a straight form,'and Fig. 6 is a view of a detail.

As shown in Fig. 1, a transparent tube 1, thermometrically bored, opens at, each end into a diffusion chamber 2 composed of a heat resisting liner 3 and a surrounding metal or other tube 4. The liner maybe made of wood, rubber, or any other suitable material. At the other end of the diffusion chamber is'secured a plug or septum 5 of porous material through which the gases difl'use. The porous material may be com-- posed of carbon, unglazed earthenware, paper dip ed into collodion, rubber, or so forth. Caps or plugs 6, of non-porous niaterial, are retained'in tubes 7, by pins 8, which 7passing through'curved slots 9 in the tubes serve to bring the plugs 6 close up .against their respective septa 5, so as to prevent diffusion, or allow of their with- .drawal to a distance suflicient to admit of.

the passage of the, surrounding gas through the slot 9, or other orifice, into the space opened below the septum and thence through the latter. I

For clearness,-one of the slots 9 has been they are horizontal-at their upper ends.

a A fluid or other. index 10 is provided in .shown as facing toward the center of the the tube, saidindex being displaced along the tube when the pressure differs on either side of it. The tube and index will be re- Iferred to as an indicator.

The normal position of the index is at the center. of the tube 1. The penetration of a=foreign gas into the diffusion chamber 2 will cause it to move in one direction or another according to whichever for such indices as mercury; the decrease for alcohol and certain other indices.

Instead of accurate calibration, it would do equally well for some purposes, to hide or cover the index when in the neighborhood of zero, and only to allow it to be seen, on emerging from the cover, when it has moved considerably. Thus, if .used in coal mines, no needless alarm would be caused by its slight movements about zero, but it would become visible as soon as a real danger threatened. A There are one or more subsidiary septa 11 fitted to and communicating witheach chamber and with a fresh gas reservoir 12 formed in this case by two channeled rings 13, 14, hermetically joined to one another attheir outturned rims 15, 15. This arrangement has for its purpose to purge or free,

either automatically or otherwise as deemed deslrable or necessary, the chambers 2 fromthe admixed gases which accumulate therein, by way of the main permeable media 5. A. lead or other tube 16 contained within the fresh gas reservoir 12, and opening into it at one end, passes at the other end 17,

securely into the tube.

through a hole in one of the rings 14. All communication with the reservoir, however, is prevented by a short column of liquid; the function of the tube 16 is to keep the gas in the reservoir 12 at a constant pressure despite chan es of level and temperature. This it does, or the oil column is forced one 1 way or another along the tube 16 as the vol- -ume of gas increases or decreases. The dimensions of the tube 16 and position of the column are obviously such that the latter is always contained within the boundaries of the tube. The column is introduced into the tube 16 when the latter is heated beyond the maximum temperature it is likely to attain. Its subsequent cooling withdraws the column The annular form of the apparatus above described, particularly adapts it for use in combination with certain kinds of miners lamps, upon the cylindrical body of which it can be securely fixed. For most purposes to which this and the following forms of the invention are to be applied, air is used as the standard comparative gas, and is the one'originally inclosed within the diffusion chamber. An additional supply of it is then, of course, inclosed in the fresh gas reservoir. These two st "ps occurv during the manufacture of the de' ice.

When not in use, the 'orous septa are closed by their respective lilocks 6; to take a reading, one of them should be uncovered; another reading could then be obtained by closing this last one and opening the other.

Fig. 3 shows an upri ht form of the apparatus, in which the iflusion chambers 2 are both situated inan ebonite or similar block 18. Similar reference numerals refer to like parts, a pocket 19 serving the purpose of the tube 16 with its movable column in the just described form; said-pocket 19 is constructed of material having sufficient give and resiliency to allow :of-the air in the reservoir 12 remaining at constant pressure under a varying temperature. It is secured .to a band 20, hermetically sealed in the cover of the reservoir '12, and its interior is open to the atmosphere or other surrounding gas.-

Fig. 4 shows how a mercury or similar indexlO can be used, to inake or break an electric circuit which in this case is composed of a battery 21, a lam'p 22, and contacts 23, 24, 25, passing through the glass tube 1, 25 being in constant contact with the mercury, while one of the others 23 or 24 is in-contnct when the index has risen high enough on one side or another, and the circuit is then completed. Obviously such a circuit could, by means of a relay, or so forth, be made tov control the whole of the mines or other electrically driven machinery.

vFig. 5 shows a straight form of the device, 26 being a metal frame and 27 caps screwing on to-its ends and serving when removed -to expose their respective porous septa-5. I

Fig. 6 shows another device for covering or uncovering the porous septa 5, two pins 28 pass through the yoke 29 and carry eccentric pads 30, which in their normal ,positions cover the septa 5, but. can be caused to uncover them in part.

In operation, both chambers and the vessel are exposed to fresh air or neutral gas; the whole of the inlets are then closed with the reception of the permeable connection between the chambers and those between the latter and the reservoir; The apparatus is now ready for carrying out a test which is effected by exposing one of the chambers at theplace where it is desired to make the test. The maximum reading of the indiner similar to that above described.

Te claim: a t

1. A device for indicating the difi'usive action of gases, comprising a closed chamber, a porous septum or diaphragm arranged in the walls of said chamber, the interior ofthe latter having communication with the exterior atmosphere only'through said p0- rous septum, a device having communication with -said chamber for indicating the pressure of gas within the latter, a cover for said porous septum consisting of material impervious to gases, a sleeve or socket in a which said cover is adapted to move, said sleeve or socket being provided with a slotted opening in its wall, and a pin attached to said cover and projecting through said slotted opening to allowof said vcover being moved toward and from said 'porous septum, said slotted opening further serving for the admission of gas so that it may pass through said porous septum.

2. A device for indicating the diffusive action of gases, comprising a closed chamber, a porous septum or diaphragm arranged in the walls of said chamber, the intum consisting of material impervious to.

gases, a sleeve or socket in which said cover is adapted to move, said sleeve or socket being provlded w1th a, slotted opening in its wall, and a pin attached to said cover and projecting through said slotted'opening to allow of said cover being movable toward and from said porous septum, said slotted opening further serving for the admission of gas so that it may pass through said porous septum.

3. A device for indicating the diflusive action of gases, comprising a closed chamber, a porous septum or diaphragm arranged in the walls of said chamber, the

interior of the latter having communication with the exterior atmosphere only through said porous septum,.a device-hav- 7 ing communication with said chamber for indicating the pressure of gas within the latter, means for covering tor uncovering said porous septum to prevent or. allow the passage of gas therethrough, a second closed chamber adapted to contain'fresh air or other gas arranged adjacent said first named closed chamber, and a-second porous septum or dlaphragm arranged in latter, means for covering or uncovering' said porous septum to prevent or allow the passage of gas therethrough, a second closed chamber adapted to contain fresh air or other gas arranged adjacent said first named closed chamber, a second porous septum or diaphragm arranged in the walls of said first named closed chamber aiiord- 5 ing communication between said two closed chambers, and means for regulating the pressure of the gas within said secon named closed chamber, 5. A device for indicating the diffusive action of gases, comprising a closed chaniher, a porous septum or diaphragm arranged in the walls of said chamber, the interior of the latterhaving communication with the exterior atmosphere only through said porous septum, a transparent tube communicating with said chamber having a movable body of liquid therein for indicating the pressure of gas within said chamber, a cover for said porous septum consisting of material impervious to gases said cover serving, when'in operative position, to prevent the passage of gas throughsaid porous septum, a second closed chamber adapted to contain fresh air or other gas arranged adjacent said first named closed chamber, and a second porous septum or diaphragm arranged in the walls of said first named'closed chamber afi'ord-' ing communication between said two closed chambers.

6. A device for indicating the diffusive action of gases, comprising a closed chamsaid chamber, a cover for said porous septum consisting of material impervious 'to' gases said cover serving,'when in operative: position, to prevent. the passage of gas through said porous septum, means for moving said cover toward and away from said porous septum, asecond closed chamber adaptedto contain fresh air or other gas arranged adjacent said .first named closed chamber, a second porous septum or diaphragm arranged in the walls of said first named closed chamber afiording communication between said two closed chambers, and a tube communicating with the interior of said secondclosed chamber and also communicating with the exterior atmosphere adapted to contain liquid so as to maintain the pressure within said chamber at the desired standard.

7. A device for indicating the diffusive action of gases, comprising a. closed chamher, a porous septum or diaphragm arranged in the walls of said chamber, the

.interior of the latter having communication with the exterior. atmosphere only through said porous septum, a device havseptum arranged in the walls of said first named closed chamber affording communi-- cation between said two closed chambers.

8. A device for indicating the difiu sive action of gases, comprising a closed chamber,

a porous septum or diaphragm arranged in the walls of said chamber, the interiorof the latter'having communication with the exterior atmosphere only through said porous septum, a transparent tube communicating with said chamber said tube having a movable body of liquid therein for indicating the pressure of gas within said chamher, a cover for said porous septum consisting of material impervious to gases, means for moving said cover toward and away from said porous septum,.asecond closed chamber partially surrounding said first named closed chamber and through which the latter passes, a'second porous septum arranged in the walls of said first named closed chamber afiordin communication between said two closed c ambers, and means for regulating the pressure within said second namedclosed chamber.

9.- A device for indicating the difiusive actionof gases, comprising a pair of closed chambers, each chamber being prpvided with a porous septum or .diaphragm'arranged in the walls thereon-the interior of each chamber having communication with the exterior atmosphere only through said porous septa, a device connecting said pair of closed chambers and having communication with' the interior of each for indicating the pressure of gas within said chambers, and means for covering or uncovering said porous septa to prevent or allow the passage of gas therethrough.

10. A device for indicating the diffusive action of gases, comprising a pair of closed chambers, each chamber belng provided with a porous septum or diaphragm arranged in the walls thereof, the interior of each chamber having communication with the ex- .teri'or atmosphere only through said porous septa a device connectingsaid pair of closed chambers and having communication with the interior of each for indicating the pressure of gas within the chambers, and a coverfor the porous septum of each chamber consisting of material impervious to gases, said cover serving when in operative position to prevent the passage of gas through the porous septa.

11. A device for indicating the diffusive action of gases, comprising a pair of closed chambers, each chamber being provided with a porous septum or diaphragm arranged in the walls-thereof, the interior of each chamber' having communication with the exterior atmosphere only through said porous septa, a transparent tube connecting said pair of closed chambers and having commu-' nication with the interior of each, said tube having a movable body of liquid contained therein for indicating the pressure of gas within the closed chambers, and means for covering or uncovering said porous septa to prevent or allow the passage of gas therethrough.

12. A device for indicating the, diffusive action of gases, comprising a pair of closed chambers, each chamber being provided with a porous septum or diaphragm arranged in the walls thereof, the interior of each 'chamber having communication with the exterior atmosphere only through said porous septa, a transparent tube connecting said pair of closed chambers and having communication with the interior of each, said tube having a movable body of'liquid contained therein for indicating the pressure -of gas within the closed chambers, a cover said cover and passing through said slotted opening for moving said cover toward and away from sald porous septum.

13. A device for indicating the difiusive action of gases, com risin apair of closed chambers, each cham er being provided with a porous septum or diaphragm arranged in theiwalls thereof, the interior of each chamher having communication with the exterior atmosphere only through said porous septa, a device connecting said pair of closed chambers and having communication with the interior of each for-indicating I rous septa to preventor allow passage of gas.

the pressure of gas within said chambers,

means for covering or uncovering said potum arranged in the walls of each of said her.

pair of closed chambers for affording communication between each of said pair of closed chambers and said last namedcham- 1ft. A device for indicating the diflusive actlon of gases, comprising a pair of closed chambers, each chamber being provided with a porous septum or diaphragm arranged in the walls thereof, the interior of each chamber having communication with the exterior atmosphere only through said porous septa, a device connecting said pair of closed chambers and having communication with the interior" of each for indicating the pressure of gas Within said chambers, a chamber adapted to contain fresh air or other gas arranged adjacent said pair of closed chambers andv a porous septum ar ranged'in the walls of each of said pair of closed chambers for aflording communication between each of said pair of closed chambers and said last named chamber.

15. A device for indicating the diffusive actionof gases, comprising a pair of closed chambers, each chamber being provided with a porous septum or diaphragm arranged in the walls thereof, the interior of each chamber having communication with the exterior atmosphere only through said porous septa, a device connecting said pair of closed chambers and having communication with the exterior of each for indicating the pressure of gas within the chambers, a

closed chamber adapted to contain fresh airor other gas partially surrounding said first named chambers and through which the latter pass, and porous'septa arranged in the walls of said pair of closed chambers for affording communication between the latter and said last named closed chamber.

16. A device for indicating the diffusive action of gases, comprising a pair of closed chambers, each chamber being provided with a porous septum or diaphragm, ar-

ranged in the walls thereof, the interior of each chamber having communication with theexterior atmosphere only through said porous septa, a device connecting'said pair of closed chambers and havin -.communication with theinterior of each or indicating the pressure of gas within the chambers, means for covering or uncovering said porous septa to prevent or allow the passage of gas. therethrough, a closed chamber adapted to contain fresh air or other gas partially surrounding; said first named chambers and through which the latter pass,

porous septa arranged in 'the -walls of nd regulating the pressure of the pair of closed chambers for affordin comaction of gases, comprising a pair of closedchambers, each chamber being provided 'with a porous septum or'diaphragm arranged in the walls thereof, the interior of each chamber having communication with the exterior atmosphere only through said porous septa, a transparent tube connecting said pair of closed chambers and having communication with the interior of each,

said tube having a movable body of liquid contained therein for indicating the pressure of gas within the closed chambers, a cover for the porous septum of each of said chambers, means for moving said covers toward and away from said porous septa so as to prevent or allow the passage of gas through the latter, a closed chamber adapted tocontain fresh air-of other gas partially surrounding said first named chambers and through which the" latter pass, porous septa arranged in the walls of said pair of closed chambers for afl'ording.

communication between the latter and said last named closed chamber, and means-for gas within said last named closed chamber.

' 18. A device for indicating the diffusive action of gases, comprising a pair of closed chambers, each chamber being providedwith a porous septum or diaphragm .ar-

rangedin the walls thereof, the interior of.

each chamber having communication with theexterior atmosphere only through said porous septa, a transparent tube connecting said pair of closed chambers and having communication with the interior of each,

said tube having a movable body of liquid contained therein for indicating the pressure of gas within the closed chambers, a cover for the porous'septum of each of said chambers, means for moving said covers toward and away from said porous septa so asto prevent or allow the passage of gas through the latter, a closed chamber adapted to contain fresh air or other gas arranged adjacent said pair of closed chambers, means of commun cation between each of said pair of closed chambers and said last named chamber, and means for regulating the pressure of gas within said last named chamber. 1 4

19. A device for indicating the diffusive action of gases, comprisinga pair of: closed chambers, each chamber be ng pro 'vided with a porous septum or diaphragm arranged in. the walls thereof, the 'interior of each chamber having communication with the exterior atmosphere only-through said porous septa, a transparent" connecting said pair of closed chambers -and having said porous septa for preventing or allow-- ing the passage of gas through the latter, 'a closed tubular chamber partially inclosing said pair of closed chambers and through which the latter pass, said tubular chamber being of ring shape so as to be adapted to surround a lantern or the like,

' porous septa -arranged in the walls of said pairof closed chambers for affording communication between the latter and said last 15 named chamber, and a tube communicatin with 'the interior of said last named closed chamber and having communication with theexterior atmosphere for maintaining the pressure within said last named chamber at 20 the desired standard.

In testimony whereof we aflix our signatures in presence of two witnesses.

I FREDERICK JAMES TURQUAND. 5-- WILLIAM EDWIN GRAY. Witnesses: ARTHUR H. STANLY, CLAUDE A. HADLEY. 

